As intelligent terminals are applied widely, requirements for data services grow exponentially. To meet people's requirements for Internet access anytime and anywhere, performance of a network system must be improved.
In some communications systems, a signal field at a physical layer of a data packet provides a partial association identifier field for carrying partial association identifier (partial AID) of a target receive end of the data packet, so that a receive end may determine the target receive end of the data packet by using the partial association identifier at the physical layer. Therefore, for example, if the receive end is not the target receive end of the data packet, the receive end does not need to continue to parse the data packet. Therefore, communication efficiency is improved, and device burden is reduced. However, due to a limit of a quantity of bits of the partial association identifier (or a quantity of available bits of the signal field), the partial association identifier can be used to distinguish only more than 500 receive ends, and cannot meet development requirements with fast increase of a user quantity. In addition, in some scenarios such as device to device (D2D) communication, a partial association ID field may be set to all zeros, and its function cannot be brought into play.
Furthermore, in a system that does not provide a partial association identifier field, for a received data packet, a receive end cannot identify a target receive end of the data packet at the physical layer, and can only perform Media Access Control (MAC) layer parsing on the data packet to acquire a MAC address carried in a MAC frame header, and identify the target receive end according to the MAC address. That is, after the receive end receives the data packet, even if the receive end is not the target receive end of the data packet, the receive end must also perform MAC layer parsing on the data packet, because the target receive end of the data packet can be identified only after MAC layer parsing is performed. Therefore, for a device that is not the target receive end of the data packet, device burden is increased, waste of hardware resources is caused, and user experience is affected.